Are there any rental car places that allow add on drivers under 25?

my mom and i need a rental car and im 17 so yea :)Are there any rental car places that allow add on drivers under 25?
18 is the minimum for most (but if you only drive with her next to you, she could take responsibility for any damages you cause..)Are there any rental car places that allow add on drivers under 25?
Although many companies will allow someone to rent a car at 21 (and in some circumstances, 18) the minimum age for additional drivers for most companies is 25.